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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Witold Sadowski <wsadowski@marvell.com>,
	Chandrakala Chavva <cchavva@marvell.com>,
	Sunil Kovvuri Goutham <sgoutham@marvell.com>,
	Mark Brown <broonie@kernel.org>, Sasha Levin <sashal@kernel.org>,
	linux-spi@vger.kernel.org
Subject: [PATCH AUTOSEL 6.1 06/53] spi: cadence: Fix busy cycles calculation
Date: Mon, 16 Jan 2023 09:01:06 -0500	[thread overview]
Message-ID: <20230116140154.114951-6-sashal@kernel.org> (raw)
In-Reply-To: <20230116140154.114951-1-sashal@kernel.org>

From: Witold Sadowski <wsadowski@marvell.com>

[ Upstream commit e8bb8f19e73a1e855e54788f8673b9b49e46b5cd ]

If xSPI is in x2/x4/x8 mode to calculate busy
cycles, busy bits count must be divided by the number
of lanes.
If opcommand is using 8 busy bits, but SPI is
in x4 mode, there will be only 2 busy cycles.

Signed-off-by: Witold Sadowski <wsadowski@marvell.com>
Reviewed-by: Chandrakala Chavva <cchavva@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Link: https://lore.kernel.org/r/20221219144254.20883-2-wsadowski@marvell.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-cadence-xspi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 9e187f9c6c95..d28b8bd5b70b 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -177,7 +177,10 @@
 #define CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op) ( \
 	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_DCNT_H, \
 		((op)->data.nbytes >> 16) & 0xffff) | \
-	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_NUM_OF_DUMMY, (op)->dummy.nbytes * 8))
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_NUM_OF_DUMMY, \
+		  (op)->dummy.buswidth != 0 ? \
+		  (((op)->dummy.nbytes * 8) / (op)->dummy.buswidth) : \
+		  0))
 
 #define CDNS_XSPI_CMD_FLD_DSEQ_CMD_4(op, chipsel) ( \
 	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R4_BANK, chipsel) | \
-- 
2.35.1


       reply	other threads:[~2023-01-16 14:02 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20230116140154.114951-1-sashal@kernel.org>
2023-01-16 14:01 ` Sasha Levin [this message]
2023-01-16 14:01 ` [PATCH AUTOSEL 6.1 38/53] spi: spidev: fix a race condition when accessing spidev->spi Sasha Levin
2023-01-16 14:01 ` [PATCH AUTOSEL 6.1 39/53] spi: spidev: remove debug messages that access spidev->spi without locking Sasha Levin

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